


Curing Deanmons 101

by waywardavengers (herax97)



Category: Supernatural
Genre: BAMF Castiel, Demon Dean, Demon!Dean, Destiel - Freeform, Dirty Talk, Dubious Consent, Eventual Happy Ending, M/M, Moral Dilemmas, Post Season 9, Seduction, Sexual Tension, Taunting, deanmon
Language: English
Status: Completed
Published: 2014-11-25
Updated: 2014-11-30
Packaged: 2018-02-26 19:45:08
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,132
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2664101
Author URL: https://archiveofourown.org/users/herax97/pseuds/waywardavengers
Summary: <blockquote class="userstuff">
              <p>
  <i>Dean winked, eyes flashing black as he settled comfortably into the chair. Castiel's hand tightened around the silver flask. "Ooh, gonna splash me again? I always knew you were sort of violent but I'm starting to think this is a bit of a kink for you."</i>
</p><p>
  <i>The flask was slammed down onto the table and Castiel stormed from the room without a look over his shoulder. "You're too sensitive!" Dean shouted after him, his laugh echoing even after the doors were closed and locked once again.</i>
</p><p>Sam has run out of blood for the demon cure and Castiel is left in charge of Dean while more is retrieved. Castiel is determined to appeal to the human side he hopes still resides in Dean. The Deanmon, however, sees this as the perfect opportunity to mentally break down his guard-angel and escape his unwanted transformation back to humanity. And if he manages to bed said angel in the process, all the more kudos to him. Post season 9 Deanmon/Castiel</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> Demon!Dean's short time with us made me sad and so did the lack of interaction with Castiel pluuus I realized I hadn't posted in over a year so I'm going for a multichaptered Destiel story. We'll see how this works out...

The air in the basement was heavy and reeked of demonic possession, a smell Castiel had long since grown used to. But this time was different, because the distingushing smell of sulfur was mixed with a scent that had grown on the angel and he had started to connect to a feeling of safety. But now it was all wrong. 

Manhandling the snarling Dean -the demon- down into the demon proof cell had been mentally draining. The aura of Dean's soul had always been dark, yes, but the love and sacrifice had been palpable. A heavy emphasis on the had been. The lack of care Castiel had practically tasted on his tongue was worse than any anger or hatred or sorrow he had ever witnessed from Dean. For someone with so many beautiful and complex emotions to be mutilated into something so passive and... dead. If Dean could not be cured, Castiel would not allow for this thing to keep on breathing. 

Trying to calm his troubled mind, Castiel started to count the flecks of dust in the air, in hopes of it distracting him from the muffled and pained sounds coming from the other room. Sam had left Castiel alone to watch over the demon while he'd gone out for more blood. They'd assumed it was safe for now, while the monster was still mostly knocked out from the treatment. But Castiel still had an uneasy feeling about it. 

After counting five hundred and eighty one pieces of dust, a low grumble made Castiel rush over to the door. Was Dean making another attempt for escape? Listening through the thick bookcase, he finally made out words instead of grumbles. "Sammy? Hello? Cas, guys, please..."

In a heartbeat, the doors were pushed open and Castiel stormed into the room. Dean's head was limp, chin resting on the slowly rising chest. "Dean?" Unable to hide the tinge of hope - hope that maybe the cure had worked and that his Dean was back - Castiel ventured closer to the demon than Sam had advised. "Dean," he tried again, voice raspy from the low volume, afraid that any sudden noise would startle Dean. 

"Cas," came the almost inaudible reply, followed by a quiet whisper that not even Castiel's ears picked up on. Throwing caution out the window and slamming the shutters, Castiel leaned in close, arms braced on either side of Dean. The timidness of Dean's voice and his frail appearance was enough to fool Castiel into forgetting what sly creatures demons could be. 

His trenchcoat was suddenly hooked in a vice-like grip and pitch black eyes stared straight into Castiel's soul as Dean's head raised. "You always were so damn gullible," the demon taunted. The snarl that followed finally shocked Castiel into retreating, leaving Dean with a torn piece of tan material in his hand. Castiel's face set into a harsh expression and for anyone other than Dean, it would have been hard to notice the jumble of hurt swimming behind the stinging blue gaze. 

"What is the meaning of this?" Castiel hissed, angrily shoving off the now ruined coat and tossing it into the corner. Honestly, he was surprised that the jacket was all Dean had attacked. 

The demon shrugged, eyes back to their usual vibrant green. The smug smirk still conveyed the menacing thoughts racing through his head. "Bored. Just wanted to mess around with you for a bit before my dear brother Sammy comes back and starts to burn me from the inside out again."

One of Dean's eyebrows cocked and Castiel sniffed, turning away from the demon. He should have known better than to think the cure would have just suddenly worked. Dean had been right about one thing - he really was gullible. Especially when it came to Dean.

"Oh, come on, Cassie. Don't be such a party pooper. Let's have a chat. Y'know, before you guys start slicing and dicing when the cure doesn't work."

Ignoring the too-gleeful words and the spark of anxiety they ignited, Castiel trudged out of the room, back even more rigid than usual. "I won't be a part of your games."

"Oh, I see. Guess Sam will be your favorite now. You gonna make a _profound_ bond with him, too? Maybe you can start the bonding while you burn my corpse. Who knows, maybe you guys will be even closer than we were. I mean, you've only done the dirty once and you were stabbed afterwards. Sam could probably teach you a few things, even though he's gotten a bit rusty, what with all his fuck-buddies dying horribly-"

Holy water splashed over Dean's face and anguished screams filled the room along with the sound of his skin burning. From the wheezing as Dean caught his breath, a low chuckle formed, evolving into a smug, taunting laugh. "I'm sorry, did I push a sensitive button there? Do you maybe have a thing for my brother, Cas? Naughty." Dean's grin was wide and Castiel itched to wipe it off with more holy water.

"Your taunting is useless so you might as well just shut up," Castiel commanded, his voice ringing through the small space. Dean raised his eyebrows mockingly, conveying a look of fake hurt.

"Shut up? But I thought our conversation was just starting to flow. Honestly, I don't mind that you want to stick it to my brother. He's a good looking guy and he's probably going to feel lonely after he kills his own brother. I'd owe you big time if you... kept him company." Dean winked, eyes flashing black as he settled comfortably into the chair. Castiel's hand tightened around the silver flask. "Ooh, gonna splash me again? I always knew you were sort of violent but I'm starting to think this is a bit of a kink for you."

The flask was slammed down onto the table and Castiel stormed from the room without a look over his shoulder. "You're too sensitive!" Dean shouted after him, his laugh echoing even after the doors were closed and locked once again.

...................

Gas pumped into the sleek Chevrolet Impala, the run-down gas station casting a shadow on the car and it's owner. The area surrounding the gas station was completely abandoned, save for Sam Winchester and the teen sleeping at the service counter inside the station. 

Even though he had only been gone for a few hours, Sam still felt the need to check up on Cas. He'd been nervous to leave the angel behind with his now-demonic brother but it had been the only thing to do if they wanted to cure Dean. 

Unlocking his phone, he dialed Cas' number, eyes distractedly following a stray car that drove past and continued down the abandoned road. 

The phone rang three times. Four. No one picked up. Sam's stomach immediately twisted with knots of worry. What if something had happened? He should have known better than to leave Cas alone with a freaking Kain-marked demonic hunter, he should never have left them, if anything happened to either of them it was his fault, it would have been smarter to send Cas for blood, no, that was an awful idea, Cas had never been a very talented liar and Sam could barely handle Dean alone and oh god, what if Dean had killed Cas? Pick up Cas, come on, pick up the goddamn phone-

"Sam?"

Air finally escaped from Sam's lungs and the worried thoughts unraveled, but only for a moment. Cas' tone suggested something was wrong. 

"Did something happen? Are you okay, is he-"

"Your brother is fine," Castiel cut in. "For now." Sam frowned, detecting a great mix of emotions in Cas' voice. The added comment didn't calm Sam's unease but he decided not to comment on it. For now. "He is very disturbing in this state."

Sam sighed. He had become painfully aware of that fact when his own brother had tried to slice him open. "Yeah, no kidding. Just don't let him get to you, alright? You know he doesn't really mean it. As soon as we fix him, everything will be okay," he assured with conviction that was so glaringly fake that it would be a wonder if Cas didn't pick up on it. 

It would have been a complete lie if Sam said that Dean's words had had no effect. The pessimism and the words purely designed to hit a sore spot had done their intended damage. But despite that, he would not give up on his brother, demon or not. 

"I will try my best to ignore him," Castiel promised. Even through the phone, the lack of faith in this simple plan was audible. "How long will it be until you return?"

Sam balanced the phone between his shoulder and ear, extracting the hose from the car and putting it away. "Hopefully sometime during the night, if I'm awake enough to drive. I'll try to hurry back... just in case," Sam promised, just as anxious as Cas to get back and get this over with. 

A rumble of approval came from the other end of the line. 

"Just be careful, Cas," Sam said in parting as he headed inside to pay for the gas and to grab coffee for the road. 

"I will-" Castiel was cut off by a loud jangling sound that carried through the phone. "I have to go," Cas rushed out. Sam's reply of 'call if you need me' was cut off mid-sentence, leaving him in the dull noise of the struggling gas pump with a growing feeling of worry in his mind. 


	2. Hook, Line and Sinker

**Notes for the Chapter:**

> Not proofread because it's 1 AM and I suck. Will be proofread and edited later when I'm not supposed to be asleep. Thanks for the kudos, here's seductive Deanmon

“Oh, Cassie? Here, Cassie, Cassie, Cassie...”

Dean's mind was growing restless with every single moment he spent cooped up in here, even more so without Castiel to taunt. Ever since he'd come so close to seeing Sammy's blood flow freely... He was craving for the kill and since Castiel had torn it from him when he'd been seconds away... Well, it just felt like justice that the angel pay in some way. Preferably decapitation, or maybe Dean could dismember him, one digit at a time, one limb, just to make it last. But before that happened, Dean needed to claim something that he'd wanted for a long, long time. And this new Dean, he got whatever he wanted.

“I promise I'll play nice, Cas,” he tried again, knowing very well that the angel could hear him. However, that also meant Dean could hear him and as soon as he started to really listen, it was obvious what Cas was doing. “You're ratting me out to Sammy?” Dean laughed mockingly, straining his ears in hopes of catching more of the conversation. 

Upon hearing that Castiel was urging Sam to hurry back, Dean felt that the little chat had gone on for long enough. Since his shouts hadn't been effective so far, Dean jerked back in the chair, back slamming into it. It wobbled just so before hitting the ground with a firm thud. Along with that, Dean started shaking the stupid cuffs keeping him trapped here, almost positive that the racket would draw a suspicious Castiel in here.

Mere moments later, he proved right. The fierce, blue eyes were burning with anger as Castiel stormed into Dean's personal holding cell. “What are you doing?” the angel growled at him. Dean's blood rushed. That anger was so damn enticing in so many different ways. His skin tingled at the mere thought of what he had planned for his little guard dog.

“I wanted to get your attention but you very busy with my little brother, so I figured drastic times...” Dean grinned deviously, settling back in the chair. 

“Why did you need my attention?” Castiel retorted, still hovering in the doorway, as if he was frightened to come any closer. And with good reason, Dean thought. But he would have to change that. He need the angel close; close enough to smell the anger-mixed-fear, close enough to see every single emotion that would flash in the blue orbs, close enough so that he could hold him and touch him until he begged for mercy and then Dean would give him the mercy he pleaded for. Eventually. 

“Because I wanted your company,” Dean replied, tone laced with innocence and good intentions. Of course, that tone was hardly believable coming from a creature of hell, but still. Castiel merely scoffed at that, turning on the spot to leave.

Dean smirked. “If you don't, I'll just keep myself entertained by getting out of these chains. And I know you can't watch me while you're all the way over there behind a closed door.” Castiel halted, always falling so wonderfully in the traps Dean was laying down, playing his script perfectly.

Finally, Cas turned around, the scruffy face blank. “No talking,” he ordered, at last stepping into the room and taking a seat in the far corner. Settling with a rigid back into the chair, Castiel's arms crossed over his chest, the thin material of the shirt settling nicely along his biceps. 

“Fine, we can just stare at each other until Sammy gets back, then.” And that Dean did, head cocking to the side as he allowed his eyes the luxury of roaming over every inch of Castiel. Like black ink spilling over paper, Dean's eyes were engulfed in darkness.

It didn't take long for Castiel to start squirming, the blue-eyes gaze having averted to the far wall a long time ago. But that didn't stop Dean. He knew Cas knew he was being watched. Intensly.

“If you're trying to make me uncomfortable...”

“Then it's working perfectly, I know,” Dean finished for him, the smug, self-satisfied grin audible in his voice. He could feel Castiel bristle from the other side of the room, enjoying every single rise he managed to invoke in the angel. It was only a matter of time before he risked coming up close again. The torn coat had just been the beginning; foreplay, if you will. 

“You know, I've barely ever seen you look scared, Cas,” Dean pondered aloud, breaking Castiel's rule of no talking but instead he moved his gaze. It was likely that Castiel would settle for talking if it eased the staring. At least for a little while. “Like genuinely frightened. I mean, I know you've been terrified a lot of times but you've always hidden it so well. Like now, for instance.”

Castiel's interest seemed to perk up at that and Dean suppressed a joyful grin. Hook, line and sinker. “You must be nervous that you and Sammy won't be able to make me all better again, right?” Words laced with mocking and sarcasm meant another burst of anger from Castiel. “And you being the brave little soldier that you are, would of course volunteer to gank me so poor Sammy wouldn't have that on his conscience. And that has to scare you, Cassie, am I right? You've spent your entire time here on Earth trying to save one measly, little human and in the end, you're going to have to kill me.”

Dean's laugh seemed to do the trick as Castiel's chair cluttered to the ground. Dean's wrists were suddenly being restrained with inhuman strength and that oh-so-familiar musk filled his senses. “You are no human. If we can't bring Dean back then that means he's already gone and that will not have been mine or Sam's fault,” Castiel spat into Dean's face. Dean decided to use his chance while he still had it.

“The only time I've genuinely seen you look petrified was when I brought you to that brothel. Remember that, Cas? You were so innocent, a perfect little virgin, you have no idea how much I wanted to give you what you wanted, what you needed, but I was scared,” Dean rushed out but his mouth still wrapped perfectly around every word, making sure that Castiel received the full and utter intensity behind them. “But this Dean? He's not afraid of anything and he can give you whatever you desire, Cas. Don't think you can hide what you want from me, Cas. I know you better than anyone...”

Dean's mouth hovered so close to Castiel's ears, his voice low and seductive, and it was a wonder the angel hadn't moved away yet. Managing to turn his hand upwards in Castiel's loosened grip, Dean's fingers brushed the angel's wrist.

Sadly, that seemed to snap Castiel back to his senses. With a shocked and angry gasp, Castiel practically stumbled away from Dean. His eyes were wide, his fists were clenched and before Dean could even open his mouth to continue, Castiel had grabbed and unscrewed the silver flask. 

Holy water scorched Dean's skin and his teeth clenched as his face burned. “We're done here,” he heard Castiel say over his own pained grunts. When Dean opened his eyes, the doors were closing.

“You can't deny it, Cassie. Demon or not, you want me,” Dean shouted and then he was alone in the room once more, grinning and laughing to himself. His mind was brimming with possibilities, all the things he would do, all the things he would make Castiel do. As soon as the angel's urges and anger became too much to bear... Dean would get his fun and then he would quench the thirst brought on by Cain's mark. 

….....

Castiel didn't care that he shouldn't let Dean out of his sight, no matter what. He needed to get away, further than just behind the closed doors. He stumbled up the steps into the bunker's upper floors, turning into the first bathroom he located and slamming the door shut. He breathed heavily in the dark until the black began to bear an uncanny resemblance to the hellish, pitch black eyes and Castiel turned on the lights.

His heart hammered heavily against his ribcage and his breathing was uneven. But he wasn't scared, despite what his dark eyes were telling him. No, he was angry. And he felt something more. Something bad, which in all honesty, did scare him. Turning on the faucet, Castiel splashed his face with freezing water, knowing that if he could sweat, his shirt would be drenched by now. 

After his speech to Hannah about the inconvenience of feelings... Of course, he had always cared for Dean, and Sam as well. But he'd never allowed himself to think any further than that, to really indulge in just what those feelings meant. Feelings were dangerous and now, with Dean forcing out things he'd never even knew he could feel – this excitement and anger and intrigue; pure lust – feelings had just become even more dangerous. And if Dean wanted to play this game, Castiel was intent on playing it by his own rules. And he was intent on winning.

**Author's Note:**

> Hope it was satisfactory, feel free to show your love in some way!


End file.
